Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Settings

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe


Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...



Username
Password
New? Register here
Forgot your password?

Latest Posts

Archives

Recent Comments

Prev  2209  2210  2211  2212  2213  2214  2215  2216  2217  2218  2219  2220  2221  2222  2223  2224  Next

Comments 110801 to 110850:

  1. What do you get when you put a climate scientist and 52 skeptics in a room?
    On the weblink page, at the bottom, is a link to a Lateline transcript between George Monbiot and Ian Plimer. It's quite entertaining http://www.abc.net.au/lateline/content/2009/s2772906.htm and Monbiot plus the presenter tackle Plimer on why he continues to use wrong (made-up) data and false interpretations. It's fascinating to see how Plimer evades the questions and no doubt he will trot out the same arguments if on stage tomorrow. Oh and on the Schneider program I thought the bank balance analogy was better than the bathtub one!
  2. Climate and chaos
    Not necessarily a very good analogy, BP, since the bird isn't just a statistical outlier from the same distribution as the rest of the heavy objects. Its behavior can be ascribed to obvious physical processes. Climate is very "noisy" at short spatial and temporal scales. Thus, one can almost always find some individual location that's abnormally cold at some particular point in time. Pointing to such areas may convey a misleading impression of long-term trends in global climate. I think my lengthy comment above provides a more useful framework for understanding things.
  3. Berényi Péter at 00:24 AM on 9 September 2010
    Climate and chaos
    Or like claiming that because a birdie dropped from the leaning tower of Pisa flies away happily, dropping objects heavier than air does not necessarily make them fall down.
  4. A detailed look at climate sensitivity
    cruzn246 writes: Could anyone explain how it got almost 3C warmer than now prior to the last Ice age with lower CO2 levels? There are several contributing answers to this. First, the fluctuations you see in Fig. 1 took place over long periods of time -- by comparison, the modern CO2 & temperature increase is just getting started. Second, despite the caption to Fig. 1, it's not necessarily certain that global temperatures were that much warmer during the previous interglacial; the ice cores presumably weight temperatures in the Antarctic and the Southern Ocean more heavily than the rest of the globe. Third, as scaddenp and Tom Dayton note, there are other factors at play. As just one example, if we stopped emitting sulfate aerosols and let the atmosphere clear for a few months, we'd find that the radiative forcing from CO2 was being masked by aerosol cooling. Obviously, heavy industry was not quite as much of a factor 120,000 years ago! There's probably other points that I'm forgetting, too. The bottom line is that there's no one single answer to that question; it's a combination of multiple effects.
  5. Climate and chaos
    Did you actually read the article you linked to, BP? The existence of an anomalously cold winter in parts of South America is a fact, but there's actually a great deal of uncertainty about the specific event you're referring to and the relative importance of different causes. In any case, you apparently missed the point of my comment. Claiming that individual cold snaps in place X or place Y are somehow meaningful indicators of trends in climate is like claiming that individual cases of infant deaths here or there mean that we haven't made any progress on reducing infant mortality rates. Or like claiming that because your uncle Afred was a lifelong smoker and lived to be 92, smoking does not reduce life expectancy. Emotionalism isn't a very good substitute for reasoning, IMHO.
  6. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    HumanityRules writes The NODC near realtime update of OHC shows that the oceans haven't been warming since 2004ish. That's exactly the problem. You're picking out a specific year and saying there's no warming after that. We already know the data fluctuates quite a bit, look at the few years before that for an example. The ocean didn't warm that quickly, the data bounces around because we lack sufficient measurement of it.
  7. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Ken says: So in answer to Ned - the oceans have a storage capacity at least 30 times that of all other combined sinks - thats about 96% - so I would think that what happens in the oceans is crucial to the whole AGW story. Yes, nobody disputes this. The questions are how do we interpret what is happening in the ocean, and how much weight do we give our interpretation of that vis-a-vis our understanding of other components of the climate system. You keep citing BP's remarks earlier, which seem to have impressed you greatly. Others, however, are less impressed. With a certain degree of trepidation lest I be misrepresenting something, I would characterize his argument as follows:
    (1) If we assume that individual year-to-year wiggles in the OHC data were valid representations of interannual variability in OHC, that would lead to physically unrealistic conclusions about the planetary radiative imbalance. (2) Therefore, there's no reliable evidence of long-term warming in the OHC data. (3) From this, we conclude there's no long-term warming in the ocean.
    That is, at least, how BP's (and your) claims appear to me. But (1) is obviously a straw-man argument, (2) does not follow from (1), and (3) does not follow from (2). Again, Ken, I've seen you refer to this line of reasoning many times on this site, so clearly it seems convincing to you. I think there are serious flaws in it. We can't both be right; presumably, science will continue to progress and sooner or later the answer will be obvious to everybody, one way or another.
  8. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    CBDunkerson writes: Darnit Ned... if you're always gonna say the same things I want to better than me then you need to type slower. :] Great minds think alike? Or folie à deux? Who can say...
  9. Berényi Péter at 23:22 PM on 8 September 2010
    Climate and chaos
    #20 Ned at 22:33 PM on 8 September, 2010 In contrast, the occasional spatial or temporal cold anomalies (like parts of the US last winter) are best described as reminders of the climate we're leaving behind. They're not representative of what most places will feel like most of the time in 2020 or 2040 or 2060. Do you mean the recent cold spell in Bolivia, unprecedented in recorded history that emptied rivers there of fish and wreaked havoc on wildlife is supposed to be a reminder of the climate we're leaving behind? Sounds funny.
  10. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Ken Lambert writes: Although Dr Pielke puts his case a little clumsily, his basic point is right. If you can't find an increase in OHC between times T1 and T2, then as oceans are the main store of heat in the Earth system - there is no warming imbalance between T1 and T2. Just a word of caution, Ken. Our inability to find X does not mean that there is no X. Let's imagine that, through some remarkable case of short-sightedness, we had collected vast quantities of data about the climate system but had somehow neglected to ever measure the temperature of the ocean. Would that failure to record a rise in OHC somehow mean that the ocean could not be warming? Obviously not! In reality, of course, the problem is not that we haven't ever measured temperature in the ocean, but that there is a great deal of uncertainty in the measurements. For those of us who have been observing this field for a long time, the experience of the MSU data from the late 1990s is a cautionary tale. Satellite microwave data from MSU showed a cooling trend that was in direct conflict with both the predictions of climate models and the trends from other data sources. And people certainly argued -- with some validity -- that the MSU data ought to be a more objective and reliable source of information on the climate. Of course, we all know the history -- a series of corrections and improvements to the methods used for processing MSU data repeatedly brought those data into closer and closer correspondence with surface temperature trends, such that today the 1979-present trends from RSS, GISSTEMP, and NOAA NCDC are all within less than 0.01 C/decade of each other. The moral of this story is that we need to look at all the pieces of the puzzle, not just one.
  11. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    As I have suggested elsewhere, measurement of OHC changes needs a baseline viz. a snapshot of the 'tiled' oceans. The 'ideal' system would be a global array of tethered buoys measuring the same 'tile' at the same time. A tile might be 500m deep by 1 degree square to have enough resolution. The gold standard would be a snapshot of temperatures of each tile at time T1 and another snapshot at T2. A summation of each would give accurate changes in OHC for the whole. The Argo buoys are at present about 3500 in number covering on average a square of ocean 330km x 330km down to 2000m. The average ocean depth is 3700m. Not all the Argo buoys are measuring down to 2000m. How close the drifting Argo come to the 'ideal' is hard to determine. For sure, strong currents will tend to coagulate drifting buoys so that the same 'tile' of ocean might might not be measured at time T2 as was measured at T1. Two or more buoys might enter a tile of ocean and leave none where a prior measurement was taken. Now this might even itself out with some sort of statistical correction, but currents moving at 3-4 knots would move buoys and water out of a tile in a matter of hours, so it would seem a difficult problem to correct back to the 'ideal' measurement system of tethered buoys. Those more expert that I might explain how this is done. I suspect that the noisy and inconsistent nature of OHC reconstructions might be due to this problem.
  12. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    The serendipitously-named commenter "SNRatio" writes: [...] it is really hard to take Pielke, HR (plus BP here) quite seriously. Looking at the historical data, there is clearly a rather low signal-to-noise ratio here, which means that heat content may be suddenly "increasing" (like after 2000), only to "decrease" slightly for several years thereafter. chriscanaris objects: BP hasn't even posted a comment yet (and may or may not want to) and you say a priori that you won't take him seriously. True, BP hasn't commented in this thread. But he has provided recent comments on this specific topic in another thread earlier this week. It's possible he has changed his position in the past 48 hours, but it seems unlikely. chriscanaris continues: Sorry, guys, but 'superstition' kind of also fails the civility test. This is in response to the final paragraph from SNRatio's comment. I wish that every one participating in this site would read that paragraph. Note that SNRatio phrases it in an objectively "centrist" position -- people on all sides should be conservative in their interpretation of noisy data, and avoid claims of significance for what may be short-term, spurious trends. That said, chriscanaris is one of the most polite and reasonable commenters on this site, and one of the very, very few commenters from the "skeptic" side whose comments I always look forward to reading. I can see cc's point about the use of the word "superstition"; and more generally speaking, it seems to me that we should take cc's perceptions of language and civility seriously. I know it's very easy for me personally to lapse into dismissive and contemptuous responses to those with whom I disagree, and it would be better if I could restrain that impulse in all my dealings on this site.
  13. Roger A Pielke Sr at 22:59 PM on 8 September 2010
    Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    In order to assure that my view is accurately presented, I am posting a comment on your weblog. I appreciate that you have provided this opportunity. There are several incorrect statements in your post. First, as long as the sampling of the ocean heat is sufficiently dense, a snapshot is not cherry picking, as there is no lag involved. A simple analog is a pot of water on the stove. When the burner is on, heat is added in Joules per second which results in the temperature increasing. By measuring the total heat of the water in the pot at any time, we can diagnosis the average rate of heating between sampling times. This integrated assessment is much more accurate than seeking to measure the heating rate itself. In terms of the climate system, the heating rate is the global average radiative imbalance (which is made up of the radiative forcings and feedbacks). The difficulty of monitoring the fluxes, as contrasted with the integrated heat changes, is discussed in a series of weblog posts involving Kevin Trenberth and Josh Willis on my weblog; i.e. My Perspective On The Nature Commentary By Kevin Trenberth http://pielkeclimatesci.wordpress.com/2010/05/24/comments-on-nature-commentary-by-kevin-trenberth/. The issue of sea ice and glacial melt is not a significant component in the global average climate system heat changes, as presented in Table 1 in Levitus, S., J.I. Antonov, J. Wang, T.L. Delworth, K.W. Dixon, and A.J. Broccoli, 2001: Anthropogenic warming of Earth's climate system. Science, 292, 267-269. http://pielkeclimatesci.files.wordpress.com/2010/04/levitus2001.pdf. As I wrote in Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335. http://pielkeclimatesci.files.wordpress.com/2009/10/r-247.pdf "[T]here are several major reasons that the assessment of the earth system’s heat budget is so valuable. • The earth’s heat budget observations, within the limits of their representativeness and accuracy, provide an observational constraint on the radiative forcing imposed in retrospective climate modeling. • A snapshot at any time documents the accumulated heat content and its change since the last assessment. Unlike temperature, at some specific level of the ocean, land, or the atmosphere, in which there is a time lag in its response to radiative forcing, there are no time lags associated with heat changes. • Since the surface temperature is a two-dimensional global field, while heat content involves volume integrals, as shown by Eq. (1), the utilization of surface temperature as a monitor of the earth system climate change is not particularly useful in evaluating the heat storage changes to the earth system. The heat storage changes, rather than surface temperatures, should be used to determine what fraction of the radiative fluxes at the top of the atmosphere are in radiative equilibrium. Of course, since surface temperature has such an important impact on human activities, its accurate monitoring should remain a focus of climate research (Pielke et al. 2002a).” The recent data (2004-2008), according to Josh Willis, is quite robust in showing no global annual averaged upper ocean warming. This is also documented in the papers Cazenave et al. Sea level budget over 2003-2008: A reevaluation from GRACE space gravimetry, satellite altimetry and Argo. Global and Planetary Change, 2008; DOI:10.1016/j.gloplacha.2008.10.004. http://sciences.blogs.liberation.fr/home/files/Cazenave_et_al_GPC_2008.pdf Willis J. K., D. P. Chambers, R. S. Nerem (2008), Assessing the globally averaged sea level budget on seasonal to interannual timescales, J. Geophys. Res., 113, C06015, doi:10.1029/2007JC004517. http://www.agu.org/pubs/crossref/2008/2007JC004517.shtml as I discuss in my post Sea Level Budget over 2003–2008: A Reevaluation from GRACE Space Gravimetry, Satellite Altimetry and Argo by Cazenave et al. 2008. http://pielkeclimatesci.wordpress.com/2009/01/07/sea-level-budget-over-2003%e2%80%932008-a-reevaluation-from-grace-space-gravimetry-satellite-altimetry-and-argo-by-cazenave-et-al-2008/. If the ocean data is further corrected for the period 2004 to 2008, I would, of course, change my conclusion. The more important issue, however, is the recommendation that upper ocean heat content in Joules be used as the primary metric to monitor global warming. In terms of the time since 2008, I suspect (and am waiting until the latest data is released this Fall) that upper ocean heating content increased during the recent El Nino. The radiative imbalance during this time period can then be compared with the models. With respect to responding to comments, I would be glad to reply on your weblog in order to further clarify my perspective. Finally, I propose that you discuss the conclusions that we reached in our paper Pielke Sr., R., K. Beven, G. Brasseur, J. Calvert, M. Chahine, R. Dickerson, D. Entekhabi, E. Foufoula-Georgiou, H. Gupta, V. Gupta, W. Krajewski, E. Philip Krider, W. K.M. Lau, J. McDonnell, W. Rossow, J. Schaake, J. Smith, S. Sorooshian, and E. Wood, 2009: Climate change: The need to consider human forcings besides greenhouse gases. Eos, Vol. 90, No. 45, 10 November 2009, 413. Copyright (2009) American Geophysical Union. http://pielkeclimatesci.wordpress.com/files/2009/12/r-354.pdf.
    Moderator Response: [Graham] Dr. Pielke - thank you for your comments. I am obliged to point out, with the greatest respect, that my argument seems to be validated by what you have written. Given the range of discussions regarding measurement, metrication and analysis, it is clear there is much work to be done, and that there is considerable uncertainty about ocean heat, its distribution and effects. On that basis, I must ask you how you come to make such definitive statements about one five year period. Your claim that the oceans did not gain heat during this period may be correct, but it is hardly proven, and certainly not representative of any consensus among those with sufficient expertise, such as Trenberth and von Schuckmann. This point of course must lead to my second observation: you have not addressed here the remark that so concerns me, and that was central to my entire argument. If ocean heat is not yet well understood, and many other indicators of global warming show warming - the cryrosphere in particular - how can you claim, as you did yesterday on your own blog, that a disputed measure of OHC "...means that global warming halted on this time period". I do not find this claim at all convincing because you do not appear to have any evidence to support it (indeed the evidence, including your own comments here, suggest the assertion is flawed), and you have not addressed these points, which are the essential premises on which my argument stands.
  14. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    HR #1, DW #7 and Ned #10 All good comments gentlemen. Although Dr Pielke puts his case a little clumsily, his basic point is right. If you can't find an increase in OHC between times T1 and T2, then as oceans are the main store of heat in the Earth system - there is no warming imbalance between T1 and T2. Where else are you going to store the heat energy? Dr Trenberth reckons on a yearly imbalance of 145E20 Joules. He puts 2E20 Joules into land heat up, 1E20Joules into Arctic sea ice melt, and 2-3E20 Joules into Total land ice melt. Thats a total 5-6E20 Joules/year out of 145E20 Joules of supposed imbalance which must go somewhere in the system. Total ice melt and land heat up is only 4%. So where is the other 140E20 Joules/year? Dr Trenberth accounts for only 20-95E20 in the oceans (a wide range), 16E20 in reduced TSI (which should probably be deducted from the 145 to start with), and a "residual" of 30-100E20 Joules which is unaccounted for. It could be in the deep oceans or 'exited to space' - ie. it was never there to start with. So in answer to Ned - the oceans have a storage capacity at least 30 times that of all other combined sinks - thats about 96% - so I would think that what happens in the oceans is crucial to the whole AGW story. Willis: DW #7 I must admit that I was unimpressed by the story of the Willis 'Eureka' moment. Argo is not anywhere near a complete story for measuring OHC - but I would expect a helluva lot better than what preceded it (XBT etc). See my next post. Von Schukmann: BP produced a comprehensive demolition of the Von Schukmann chart - pointing out the impossibilities of the bumps in the curves in terms of TOA imbalances. This is similar to the the Lymann chart above which has similar impossible jumps coinciding with the Argo-XBT transition I noted that Dr Trenberth started quoting von Schukmann to Dr Pielke Snr in an email tete-a-tete as a 'nice analysis' in April this year. Well Dr Trenberth was unaware of the Von Schukmann paper in February this year, and had expressed frustration with the inconsistency of the OHC measurements in his Aug09 paper which came to light after his now famous 'travesty' in the Climategate emails. As far as snapshots go - Dr Pielke Snr might have been reading my July 15 post revisited below.
  15. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Re: Hunt Janin (8)
    "I've read that agriculture first developed in the Fertile Crescent, maybe around 8,000 BC. I've also read that around that time (c. 6,000 BC), sea level was about what it is today. My question: is there any relationship between the rise of agriculture and sea level?"
    While this is OT, I don't believe that Skeptical Science has an appropriate post (perhaps the climate sensitivity thread comes closest) anyway, so I'll feebly attempt to answer you here. Or at least give you some leads to follow for an answer. As I mentioned previously, William Ruddiman has developed his "early anthropocene hypothesis, the idea that human-induced changes in greenhouse gases did not begin in the eighteenth century with advent of coal-burning factories and power plants of the industrial era but date back to 8,000 years ago, triggered by the intense farming activities of our early agrarian ancestors." Tied in with that is his overdue-glaciation hypothesis, in which "Ruddiman claims that an incipient ice age would probably have begun several thousand years ago, but the arrival of that scheduled ice age was forestalled by the activities of early farmers." This is possibly supported by the existence of evidence that the Amazon supported societies in excess of 20 million at one time where now stands rainforest. Related conceptually is the existence of sophisticated societies that predate that of Egypt, such as on Malta. Even older is the Jomon Culture of Japan, which also inhabited many of the islands in the archipelagos extending from Japan towards Guam. The temple of Mahabalipuram, India, are said to be the 7th. The first was located miles away, under what is now the Indian Ocean. Rising sea levels forced the building of a new temple further inland, which was then inundated. This process continued through the current iteration, the 7th. The remains of what is said to be the 6th temple are located offshore and discussed here and here. That second link references the submerged "temple" of Yonaguni, Japan. Where situated, if indeed a manmade structure, it would have been constructed more than 10,000 years ago, the last time the site was above the waters of the Pacific Ocean. Here's a quick timeline to keep in mind. Keep in mind that evidence exists for a human-decimation of North American megafauna around the time of the Laurentide deglaciation. It is theorized that human predation of megafauna 13,800 years ago caused the extinction of the wooly mammoth, allowing various plants kept in check by browsing of the herds to proliferate, changing the albedo of the Arctic and warming it. What we know: Climate sensitivity (of a doubling of CO2 concentrations) to fast feedbacks is about 3 degrees C, more or less. Hansen believes long-term feedbacks add another 3 degrees C on top of that. We know from looking at the ice core records that there is a narrow range of CO2 concentrations between glacial and interglacial periods, with a temperature range of about 6 degrees C from hottest to coldest. Effectively, even a tiny change in albedo of the planet can drive large changes in climate. So, conjecturally, if by driving the megafauna to extinction precipitated the demise of the last glaciation, giving rise to advanced agricultural societies, which through agricultural activities maintained the climate to a range conducive to the development of our modern societies (the climate "sweet spot"). A lot of hoo-hah, right? 30 years ago, who among us would've thought of this communication medium such as this? Or of what we know now of global warming? Email me if I can make better sense of this for you. The Yooper
  16. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Darnit Ned... if you're always gonna say the same things I want to better than me then you need to type slower. :]
  17. Climate and chaos
    HumanityRules writes: NASA GISS discuss Moscows summer events under the headline "What Global Warming Looks Like". This seems like an entirely reasonable headline to me. Global warming does not mean that every place will be a tiny bit warmer each year than it was the previous year. Spatial and temporal variability continues, but there are proportionately more extreme warm events and fewer extreme cold events. Eventually, conditions that were previously extreme on the warm side become normal, while conditions that were normal on the cold side become rare. Thus, the GISS headline is literally correct: the summer of 2010 is an indication of where we are headed. It is a good example of What Global Warming Looks Like -- a planet that still has spatial heterogeneity in climate, but where in a given month the few cooler-than-normal places are outweighed by a lot of somewhat-warmer-than-normal places and a couple of extraordinarily-hotter-than-normal places. That IS what global warming looks like, HR, and GISS is entirely correct to say so. In contrast, the occasional spatial or temporal cold anomalies (like parts of the US last winter) are best described as reminders of the climate we're leaving behind. They're not representative of what most places will feel like most of the time in 2020 or 2040 or 2060. So the asymmetry you object to in how people respond to warm vs cold anomalies is actually entirely reasonable. HumanityRules continues: It's actually possible to be equally clear about the Pakistan and Moscow events being linked to very specific weather conditions. [...] It's very easy to be as clear that these events are unrelated to climate change Like CB Dunkerson, I observe that you write this with a great deal of certainty, which IMHO is entirely unjustified. How do you know that these events are unrelated to climate change? That's a remarkable statement, one that's far more extreme than anything one generally sees from the "mainstream science" position on this website (and far more radical than anything in the GISS article you dismiss as "propaganda"). I'm sure you're familiar with the "loaded dice" analogy. AGW doesn't deterministically and singlehandedly cause particular heat waves, droughts, or floods. But it loads the dice in favor of more heat, and in favor of greater heterogeneity in the hydrologic cycle. When you roll a six on a loaded die, you can't say that the loading caused the six, but you can certainly say that it affected the probability (and that an abnormal string of sixes is "what the dice will look like" if we keep loading them). In contrast, HR, your definitive statement "It's very easy to be as clear that these events are unrelated to climate change" is rather shocking. HR concludes: Without resorting to bias and underhand tactics I can't explain why NASA GISS can't be equally clear about this summers events. This scaddenp is propapanda dressed up as science. I strongly disagree. The GISS article seems entirely appropriate in its discussion. Let's quote the relevant section:
    Climate anomalies in the Northern Hemisphere summer of 2010, including the heat in Eastern Europe and unusually heavy rainfall and floods in several regions, have received much attention. Are these climate anomalies an example of what we can expect global warming to look like? [...] The location of extreme events in any particular month depends on specific weather patterns, which are unpredictable except on short time scales. The weather patterns next summer will be different than this year. It could be a cooler than average summer in Moscow in 2011. But note in Figure 1, and similar maps for other months, that the area warmer than climatology already (with global warming of 0.55°C relative to 1951-1980) is noticeably larger than the area cooler than climatology. Also the magnitude of warm anomalies now usually exceeds the magnitude of cool anomalies. What we can say is that global warming has an effect on the probability and intensity of extreme events. This is true for precipitation as well as temperature, because the amount of water vapor that the air carries is a strong function of temperature. So the frequency of extremely heavy rain and floods increases as global warming increases. But at times and places of drought, global warming can increase the extremity of temperature and associated events such as forest fires.
    That's not "propaganda", that's carefully-written and entirely reasonable explanation of the relationship between underlying trends and superimposed spatio-temporal heterogeneity.
  18. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    If we look at the data over a multi-decadal time scale there is no question that 'oceans heated up, ice melted, and sea levels increased'. None. The changes in each of these areas are significant enough to dismiss any concerns about measurement error or random fluctuation producing the apparent trend. Thus, if Pielke were arguing that these things had not happened or the data could not be believed he'd be firmly in the 'denial' camp... maintaining a position solely by denying overwhelming evidence to the contrary. However, as I understand it, he is applying a narrower focus and claiming that these changes WERE happening, but have now stopped. This goes back to his underlying theory that global warming has been more due to land use changes than CO2 increases. If warming and its effects were to level off while CO2 continued to rise that would tend to validate his theory. The problem, as John pointed out in the article, is that he is basing his claim on a time frame too short to support it and, if anything, with the balance of the evidence even over that short span against him. He is making a definitive statement of global warming having stopped founded almost entirely on statistical uncertainty (i.e. all data contradicting it must be erroneous and OHC data that most think is very incomplete and uncertain being the best indicator) and his own preconceived views. Yes, it is true that highly accurate OHC data would likely be one of the best gauges of ongoing global warming... but Pielke is only assuming that the current data is that accurate (sufficient to show a change in trend over just four years), in the face of quite alot of evidence to the contrary. To me that doesn't reach the level of 'denial', but certainly demonstrates 'unfounded advocacy' rather than mere 'skepticism'. If he'd throw in a few qualifying statements (e.g. 'global warming MAY have stopped', 'ice MIGHT not be melting', et cetera) he'd be fine. However, he simply doesn't have anything like the proof needed to be making definitive statements. If anything I'd say he's reaching.
  19. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    billkerr writes: He is saying that ocean heat is the most reliable measure we have of global warming because the ocean is the largest reservoir of heat change. Hence, ocean heat change measured in joules is a superior measure to average surface temperature. This is a slightly confusing point. Ocean heat would absolutely be one of the best measures of global warming if we could measure it well. Unfortunately, the actual global measurement of ocean heat is still in its infancy. This is in contrast to many other areas (sea surface temperatures, land surface temperatures, sea level rise, mass balance of ice, etc.) where we have longer records and/or more alternative measurement options. So by all means, let's do collect as much OHC data as we can, and let's try to wring as much information as possible from the spatially and methodologically inconsistent historical record of pre-ARGO OHC measurements. But let's also recognize that while the land, the atmosphere, and the cryosphere may not soak up as many joules as the ocean, we've been studying them much longer and much more robustly, and they can tell us a great deal about the state of the climate. We need to avoid making a fetish of any one subject -- like OHC -- to the point where you override or throw out useful information provided by people studying other parts of the Earth system.
  20. Climate and chaos
    #18, the jet stream shift that caused the heat wave (Meridional flow) was of course "possible" 100 years ago and there were outlier years. But you are generally correct that the Meridional flow is more likely now than it was 100 years ago. See Figure 3.10 here www.salemstate.edu/~bhubeny/Hubeny_Dissertation.pdf for example. This particular paper does not discuss what causes the jet stream shifts. But please don't put words in HR's mouth: he did not say "caused", only "related". Also he did not mention "increased water vapor content" although it would be interesting to see how that might be linked to a jet stream shift. It seems to me that jet stream shifts have a lot more effect on water vapor than water vapor has on jet stream shifts.
  21. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    If RP, Sr. wishes to be "The Loyal Opposition" he should remain focused on the uncertainties without making such ridiculous claims that "global warming has halted" in some very short time scale. He knows better so there must be some motivation to feed the contrarian crowd.
  22. Climate and chaos
    HR #10, can you say definitively that the jet stream shift and other weather conditions (e.g. generally higher local temperatures / increased water vapor content in the atmosphere) which led to the Russian heat wave and Pakistan monsoons were even possible under the climate of a hundred years ago? If not (and the answer is definitely "not") then you REALLY need to ponder the old adage about glass houses and stones before you go start making definitive statements and accusations of scientific bias. Because even setting aside that they DIDN'T say those things were "caused" by global warming... you saying they weren't is every bit as unfounded as it would have been if they had said they were.
  23. What do you get when you put a climate scientist and 52 skeptics in a room?
    The online video is working now. Good to see it works OK outside Australia. Very good discussion, we could do with more of those. I think the woman at the end who said the bathtub analogy convinced here, raised the point of how valuable simple models and visualisations are. Such models were common in the past, educationists seem to have forgotten the importance of such methods. I remember as a teenager being fascinated by pictures of trains and clocks used to describe Special Relativity.
  24. A detailed look at climate sensitivity
    For contrast, here's the simplest possible explanation of sensitivity: http://www.ssec.wisc.edu/data/east/latest_eastwv.jpg When water vapor is uneven the earth cools, when it is more uniform the earth warms. Models show concentrated convection cools, high clouds warm, low clouds cool, upper tropospheric water vapor warms, all resulting from the distribution of water vapor. Water vapor is distributed by weather and weather is poorly modeled in GCMs at the smaller scales (local convection) where the detail is important.
  25. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    This question is, I'm afraid, off-topic but I don't know where else to post it. At least it deals with oceans... I've read that agriculture first developed in the Fertile Crescent, maybe around 8,000 BC. I've also read that around that time (c. 6,000 BC), sea level was about what it is today. My question: is there any relationship between the rise of agriculture and sea level?
  26. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    HR@1- "Given the choice is now between Willis and Trenberth who's expert opinion should we trust?" Hey, everybody makes mistakes, but now that you bring up this very issue, in your appeal to authority: Correcting Ocean Cooling "That February evening, Willis says, he was updating maps and graphs with the data that had become available since the 2006 ocean cooling paper was published. He was preparing for a talk he had been invited to give at the National Center for Atmospheric Research in Boulder, Colorado. The topic was “Ocean cooling and its implications for understanding recent sea level trends" He was looking at a map of global ocean temperatures measured by a flotilla of autonomous, underwater robots that patrol the world’s oceans. The devices—Argo floats—sink to depths of up to 2,000 meters, drift with the currents, and then bob up to the surface, taking the temperature of the water as they ascend. When they reach the surface, they transmit observations to a satellite. According to the float data on his computer screen, almost the entire Atlantic Ocean had gone cold. Unless you believe The Day After Tomorrow, Willis jokes, impossibly cold." “Oh, no,” he remembers saying. “What’s wrong?” his wife asked. “I think ocean cooling isn’t real.”
  27. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    SN Ratio @ 4: BP hasn't even posted a comment yet (and may or may not want to) and you say a priori that you won't take him seriously. Sorry, guys, but 'superstition' kind of also fails the civility test. I really don't want to see this thread degenerate and drag this site down to the lowest common denominator (pun intended :-) ). Graham, whether Pielke Sr is right or wrong is one issue. However, he returned fire with fire. I also don't think it's fair to suggest HR is 'studiously avoiding the issues.' He's addressed them pretty clearly and directly as best as I can tell. Whether he's right or wrong is again a separate issue. But let's not get caught up in a ****fight. For what little it's worth,I actually think you do owe Pielke Sr an apology. I don't think you really need to agonise about it - all of us sometimes have to do it. You also need to be charitable to those with whom you disagree. Labels dehumanise and impute bad intentions where sometimes none exist.
  28. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    I read the article that Pielke snr linked to in his reply: http://pielkeclimatesci.files.wordpress.com/2009/10/r-334.pdf He is skeptical about the IPCC for its emphasis on CO2 and long range computer modelling and some of the findings of James Hansen and associates. This is based on ocean heat measurements by Joshua Willis over a 4 year limited time frame. He is saying that ocean heat is the most reliable measure we have of global warming because the ocean is the largest reservoir of heat change. Hence, ocean heat change measured in joules is a superior measure to average surface temperature. He concedes that 4 years is a narrow time frame. All he claims in that article is that it raises issues about our level of understanding. He raises other points about other contributors to climate change and prefers to take a regional approach rather than rely on unreliable global average metrics. These are the sort of points that scientists ought to be discussing about this issue. He asserts that: "Humans are significantly altering the global climate ..."
  29. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    I tend to agree about the need for weighing words in characterizations better. But, at the same time, it is really hard to take Pielke, HR (plus BP here) quite seriously. Looking at the historical data, there is clearly a rather low signal-to-noise ratio here, which means that heat content may be suddenly "increasing" (like after 2000), only to "decrease" slightly for several years thereafter. And both Pielke and HR simply fail to draw the only sensible conslusion from the data: Avoid talking about short-time trends when the inherent variance renders such measures wildly variable. Necessitating longer observation periods. In the case of OHC, we also have a rather simple giant-scale thermometer in sea level, and that has turned out to be a much better indicator of warming than most direct temerature estimates. Any claims about warming or not warming must be checked against the basic set of indicators. Failure to do so, in my view qualifies for "denialist" or "warmist" characterizations. And in particular, to qualify as a skeptic, I have to always be on the conservative side in quality and precision assessments. Thus, for example, rather go with well established long time trends, and give up on catching eventual trend shifts early on. Drawing wide-ranging conclusions from sparse and rather crude data, looks more like superstition to me - I really can't see what that has to do with skepticism.
  30. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Scientists like Pielke have a responsibility not to put dangerous myths into the hands of those whose interests are very different from that of the majority. As do journalists :-)
  31. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Well, you did accuse him of 'denialist spin,' which in most circles would pass as an ad hominem comment. You say you're just a journalist writing about science. And I'm just a psychiatrist looking at a human interaction played out in the blogosphere. While Pielke Sr's intense reaction is a backhanded compliment to the influence of this site, it's also a reminder that we need to observe basic civility in our dealings with folks. On this occasion, I'm afraid your presentation would have got anybody's back up. I'll let HR tackle you on the science - he's better at it than I am :-)
    Moderator Response: [Graham] I agonised over this during the last 24 hours. Should I remove the remark and apologise in a footnote? Was it really lacking in civility? I made my decision. My remark stands because I don't think it is uncivil, I think it's calling a spade a spade (and compared to Joe Romm, I'm almost a fan of Pielke's). I also find the indignity expressed on this issue - what you call 'an intense reaction' - reminds me of the standard diversionary tactics I see all the time in debates like this. And in no circles would a remark about denialist spin pass as an ad hom unless it stood without any substantiation. I've now written over 3000 words on this issue, of which that remark was a single line. My remark is not an ad hom - it is an ideological association based on Pielke's record.
  32. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    gpwayne "indignant" really? You should reread his post and your post and note how many times each of you refer to the other authors emotional state, ideological outlook or ulterior motives, it should be obvious who's taking this personally. The NODC near realtime update of OHC shows that the oceans haven't been warming since 2004ish. This is based on the best data available to us. It's less than perfact but the best we've got. We have to make the most of that. Kevin Trenberth can't believe the ARGO data because he is unwilling to question the quality of his own data. It's a common fault with all flavours of scientists. It doesn't mean he's wrong but it does mean we have to take this good scientists word with a pinch of salt. Josh Willis also took part in the email exchange published on Pielkes website, He looks like the real expert on ARGO to me. Instead of simply critising the data he has been willing to accept errors in the ARGO data and actively sort to correct them. His feelings now on the data is that it's now robust and unlikely to see any future large corrections. Given the choice is now between Willis and Trenberth who's expert opinion should we trust? You haven't dealt with Pielkes main reason for being interested in this subject. The fact that good quality OHC data would be a far better metric for measuring global warming than air temperature. It seems he makes that point over and over again not because the short term trend suits his outlook but because of specific features of the climate system. If you truely want to have a scientific discussion with Pielke snr you should try addressing that issue.
    Moderator Response: [Graham] It seems to me that you are studiously avoiding the issues being discussed. You keep trying to move the debate towards something else - the validity of various metrics or the emotional nature of certain remarks - and away from the following: Pielke says the ice wasn't melting, the oceans were not heating and the sea has not been rising. And building on this array of claims for which there is plenty of evidence to the contrary (or insufficient evidence to make any claims at all), he makes the statement that global warming stopped during this period. It is these claims, the unequivocal nature of them, and the lack of rigour inherent in such assertions, that is under discussion, not issues surrounding measurements or analysis.
  33. Climate and chaos
    thingadonta - can I suggest you move this "models arent reliable". The source code for models are public domain; a massive literature covers them. What you state is valueless FUD without some evidence to back your assertion of bias unconscious or otherwise in the models. Actually I do think there is one bias in the models - that they accurately reflect known physics.
  34. Climate and chaos
    No, thingadonta, mathematicians did not redefine the concept of chaos based on their own field's "assumptions." Researchers discovered a phenomenon that exists in nature, and reused a common English word as its label, but in doing so they clearly specified its precise meaning in that technical usage. The opposite frequently happens as well--clearly defined scientific terms often become lay terms with much less clearly defined meanings.
  35. A detailed look at climate sensitivity
    crunz246, in addition to the links scaddenp provided that directly answer your questions, you should also see the more general post CO2 Is Not the Only Driver of Climate.
  36. Climate and chaos
    re 9 Tom Dayton I'll try and keep out assertions of ill intent. However, researcher bias is well-known, its not necessarily deliberate or conscious, its largely unconscious/assmumptive, and it includes experiments/models being affected by the researchers themselves not only in selection and design, but also as the experiment/model proceeds. "The key aspect of chaos is that minor changes in the starting conditions cause big changes in the local/near-term trajectory of the system" I always thought chaos was deined as a system in continual instability/flux, not just at the starting point, but ongoing, at the 'edge of chaos' so to speak. Such is also the argment for tipping points as a system proceeds. I fail to see why it should only apply at initial conditions. I had just writte the above when I checked and found that wiki actually states that mathematicians only define chaos are dependant on initial conditions (http://en.wikipedia.org/wiki/Chaos). Ah, those mathematicians are at it again-re-defining concepts based on the own field's assumptions; but wiki does mention, in passing, that this definition is done "ignoring the effects of the uncertainty principle"-which most scientists know is pervasive, ongoing over a the course of time or model or experiment, and can't actually be 'ignored' to suit assumptions in a model.
  37. A detailed look at climate sensitivity
    crunz246 - see Climate's changed before Intermediate version. You are probably also interested in CO2 lags Temperature In short - CO2 isnt the only forcing in town - its just the one causing the current warming.
  38. A detailed look at climate sensitivity
    And could someone please explain to me one time why in all the ice core data we never see temperature continue to rise when CO2 "catches up" with it on a chart. I mean logic would tell you that if the feedback thing was so true that our peak temperatures in all cycles would FOLLOW the peak of CO2. It never happens that way tough.
  39. A detailed look at climate sensitivity
    Could anyone explain how it got almost 3C warmer than now prior to the last Ice age with lower CO2 levels?
  40. A detailed look at climate sensitivity
    "A common misconception is that the climate sensitivity and temperature change in response to increasing CO2 differs from the sensitivity to other radiative forcings, such as a change in solar irradiance. This, however, is not the case. The surface temperature change is proportional to the sensitivity and radiative forcing (in W m-2), regardless of the source of the energy imbalance. " The problem with this statement is that it assumes that variation doesn't exist between different sets of climate couplings/forcings-ie the idea that negative feedback can act on one parametre and not another. Eg: lets say we increase sunlight, which for sake of argument, reduces cloud cover in temperate regions, producing a positive feedback. T rises higer than it would from solar output alone. Eg2: lets say we increase c02, which warms the tropics, which, for the sake of argument, produces more low cloud cover (more water held by air in warmer temperatures) which increases endothermic cooling due to more coulds/precipitation (same mechasim as our bodies sweating-which is also probably ocuring now with increased in rainfall in tropics with La Nina). A negative feedback from a rise in C02. In the 2 above examples, one is a strong climate senstivity with regards to the sun, the other a low climate senstivity with regards to c02. Why do the 2 sensitivities have to always be the same?? (sun/c02)? If you argue that the sun would also produce more clouds in teh tropics from the same sort of warming this isnt necassarily so, because the increase in solar output is logarithmic between the tropics and the arctic due to variation in angle of incidence, whereas c02 would be more uniform from tropics to arctic. So not only is there possibly variations in feedbacks between c02/sun, but also variations in feedbacks between various focrings between the tropics and arctic. Even if the above examples are mistaken, I just dont see how all climates sensitivities have to be the same- ie all high climate sensitivity, or all low climate sensitivity. ?? (Moreovoer the 1.2 degrees with C02 regardless of feedback isnt assured either, due to much the same sort of issues).
  41. A detailed look at climate sensitivity
    Question. At what temperature does an Interglacial Period begin in Figure 1 and at what temperature does it end?
  42. A detailed look at climate sensitivity
    The line from RealClimate is the most telling, it amazes me that people can ignore its impact: "... warmer than it has been in millions of years, ... longer than the history of huan agriculture". It amazes me that anyone believes we can cause that great a change so quickly and not expect drastic and unpleasant changes as a consequence.
  43. Climate and chaos
    Wow, HR @10, that's an amazingly biased reading of two very conservative, patient articles explaining weather and climate variability. I'd be thrilled if the people in the news media read and understood those two articles, because if they did, climate reporting would be much more level-headed, even, and accurate. If anyone is interested, NOAA has a nice interactive graphic on how arctic ice retreat can affect winter weather in eastern North America and eastern Asia. It should definitely be linked to in some of this site's responses -- like the "gee, it's cold in X today, where's the global warming?" response.
  44. What do you get when you put a climate scientist and 52 skeptics in a room?
    This is amazing
  45. Climate and chaos
    Science says extreme event will become more common, Trenberth notes that dealing with an extreme event may make the Russians realise that all in not a bed of roses with global warming. What he is not saying is that heat wave was caused by global warming. Only - get used to them because they are going to become more common.
  46. What do you get when you put a climate scientist and 52 skeptics in a room?
    We will have to live with the knowledge that most people (including me) don't have the time, energy or expertise to fully understand the situation. We are, in effect, cheerleaders on the side lines. My belief that the "difficult to convince" brigade are wrong is based less on the science than it is on their tactics. Try to get the "skeptics" to tell you which parts of the AGW argument they agree with, and they won't answer. They want to keep all avenues open, so that if the situation demands it they can argue that we are not responsible for the increased CO2 in the atmosphere, or that the CO2 makes no difference anyway, or that more is good, or whatever. The last thing they want is to agree on everything except (say) the nature and magnitude of feedbacks. Because then, if it turns out they are wrong on feedbacks, they have to accept AGW in its entirety. This actually provides a way of separating genuine skeptics from denialists. The genuine skeptic will tell you where their understanding differs from the climate scientists. The denialists won't. So to me it looks like Roy Spencer is ok. Because he is very firm on what he does believe.
  47. Climate and chaos
    Sorry, where in the NASA GISS piece does it say that the extreme events were caused by global warming? Record temperatures and extreme event are CONSISTENT with global warming but its drawing a long bow to suggest that this is propaganda not facts. I don't think the NOAA article is clear that events have nothing to do with climate change. Its pointing out that cold spells aren't inconsistent with climate change. However, I don't think we actually know a warming planet will affect the patterns responsible for those weather events yet. Papers to contrary welcome. It seems hardly surprising to me that you get more precipitation in places in a warmer world, and that if temperatures drop below zero, then it will fall as snow.
  48. Climate and chaos
    Or what about these quotes from Kevin Trenberth in a Reuters article. This is science from the scientists via the media. Don't forget the fear mongering 'War on Terror' quote from the senior scientist at the end of the piece. All good science!
  49. What do you get when you put a climate scientist and 52 skeptics in a room?
    John... You're right. That was the other thing I really took away from the piece. I couldn't help feeling like most of what Stephen was saying was going right over the heads of most of the audience. How many of those people understood what a bell curve is? Even the guy who was a doctor couldn't grasp the idea that we are accumulating CO2 over time. Or, the guy who just couldn't seem to get over the fact that 380 ppm is such a tiny number. Even the informed ones really had a long way to go to really understand what Stephen was actually saying. Scientists have to lower their sights while not sounding like they are talking down to people. That's a really tough job. Whereas it's profoundly easy for a Lord Monckton to trumpet misinformation and make people feel as though they're somehow a little smarter. I did learn something I didn't know before as well. The uncertainties regarding clouds were new to me. I've heard this information in passing before but not read or heard anything. I thought Stephen did a really good job of explaining it. This should be an ongoing series. And longer shows. People want to understand this better. Even the skeptics. I'd be all for roping each IPCC contributing author into doing a minimum of two hours of shows exactly like this.
  50. Climate and chaos
    "I suggest you get your science from scientists. " scaddenp most people don't get their science from scientists but filtered through the news. If a scientist or science institute put out a press release suggesting the Moscow and Pakistan events are tasters of whats to come from climate change it's impossible not to think that the two things are not going to become linked. In this article NOAA have been very clear in their explanation that the recent winter snows in the US are related to two weather events coming together in a rare conjugation and equally clear that these events have nothing to do with climate change. NASA GISS discuss Moscows summer events under the headline "What Global Warming Looks Like". It's actually possible to be equally clear about the Pakistan and Moscow events being linked to very specific weather conditions. These were driven by changes in the jet stream. Leading to heavy monsoon rains falling in the mountainous catchments of Pakistans rivers rather than lower down on the plains. This paved the way for the terrible flood surges. The jet stream shift also allowed hotter weather to move north over Moscow. It's very easy to be as clear that these events are unrelated to climate change but NASA GISS choose not to do this. I see why NOAA are so clear about the cold winter, some were using it to suggest the end of global warming. Without resorting to bias and underhand tactics I can't explain why NASA GISS can't be equally clear about this summers events. This scaddenp is propapanda dressed up as science.

Prev  2209  2210  2211  2212  2213  2214  2215  2216  2217  2218  2219  2220  2221  2222  2223  2224  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us